SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a94ca85770bd2e54f3bed99c8cd6e9ef8bb3aa230f790e14bb5dcebc48f6cdf3' 
  AND token = '4sZWl1pnb214xswNEqWF2NAx1NlvNUbTVuTBlVNFMGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}